Electroconductive film, roll, connected structure, and process for producing connected structure

ABSTRACT

A conductive film includes an elongated release film and a plurality of conductive adhesive film pieces provided on the release film. Then, the plurality of adhesive film pieces are arranged in a longitudinal direction X of the release film. For this reason, the adhesive film piece can be set to an arbitrary shape. Accordingly, it is possible to attach the adhesive film piece to adhesive surfaces having various shapes and to efficiently use the adhesive film piece.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/339,145, having a 371(c) date of Apr. 3, 2019, which is a nationalstage application filed under 35 U.S.C. § 371 of internationalapplication no. PCT/JP2017/034743, filed Sep. 26, 2017, which claimspriority of Japanese application no. 2016-195761, filed Oct. 3, 2016.

TECHNICAL FIELD

The invention relates to a conductive film, a wound body, a connectionstructure, and a connection structure manufacturing method.

BACKGROUND ART

In some cases, a conductive film such as an anisotropic conductive filmis used at the time of manufacturing a connection structure byconnecting a first circuit member such as an IC chip and a secondcircuit member such as a glass substrate (for example, see PatentLiteratures 1 and 2). The conductive film is one in which an adhesivefilm is formed on an entire surface of an elongated release film. Theanisotropic conductive film is formed such that an adhesive film inwhich conductive particles are dispersed in an adhesive is formed on theentire surface of the elongated release film. The conductive film isprovided as a wound body in which the conductive film is wound on a coreand is unwound from the wound body at the time of connecting the firstcircuit member and the second circuit member. Then, the adhesive film ofthe conductive film is attached to an adhesive surface of the firstcircuit member and then the adhesive surface of the first circuit memberand the adhesive surface of the second circuit member are overlappedwith the adhesive film interposed therebetween.

CITATION LIST Patent Literature

-   Patent Literature 1: Japanese Unexamined Patent Publication No.    2008-274019-   Patent Literature 2: Japanese Unexamined Patent Publication No.    2015-135748

SUMMARY OF INVENTION Technical Problem

Incidentally, the shape of the adhesive surface to which the adhesivefilm is attached becomes different depending on the type of connectionstructure. For this reason, when the adhesive film is formed on theentire surface of the release film, the adhesive film can only beattached to a rectangular adhesive surface that has the same width asthe release film. When the shape of the adhesive surface is not therectangular shape having the same width as the release film, theadhesive surface can only be attached to a part of the adhesive film inthe adhesive film provided on the release film. For this reason, theremaining adhesive film becomes useless.

Here, an aspect of the invention is to provide a conductive film capableof attaching an adhesive film to adhesive surfaces having various shapesand efficiently using the adhesive film, a wound body, a connectionstructure, and a connection structure manufacturing method.

Solution to Problem

A conductive film according to an aspect of the invention includes: anelongated release film; and a plurality of conductive adhesive filmpieces which are provided on the release film, in which the plurality ofadhesive film pieces are arranged in a longitudinal direction of therelease film.

In the conductive film, the plurality of adhesive film pieces arearranged on the elongated release film in the longitudinal direction ofthe release film. For this reason, the adhesive film piece can be set toan arbitrary shape. Accordingly, it is possible to attach the adhesivefilm piece to the adhesive surfaces having various shapes and toefficiently use the adhesive film piece.

In the conductive film, the plurality of adhesive film pieces may bespaced in the longitudinal direction of the release film. In theconductive film, since the plurality of adhesive film pieces are spacedin the longitudinal direction of the release film, it is possible toattach the adhesive film piece to the adhesive surface without affectingthe near adhesive film piece. Accordingly, it is possible to easilyattach the adhesive film piece to the adhesive surface. Further, it ispossible to further improve a degree of freedom in the shape of theadhesive film piece.

In the conductive film, the plurality of adhesive film pieces may havethe same shape. In the conductive film, since the plurality of adhesivefilm pieces have the same shape, it is possible to efficiently attachthe adhesive film piece to the plurality of adhesive surfaces having thesame shape.

In the conductive film, the plurality of adhesive film pieces may bedisposed at a center portion of the release film in a width direction.In the conductive film, the plurality of adhesive film pieces aredisposed at the center portion of the release film in the widthdirection, it is possible to easily position the conductive film withrespect to the adhesive surface at the time of attaching the adhesivefilm piece to the adhesive surface.

In the conductive film, the plurality of adhesive film pieces may bedisposed at an end portion of the release film in a width direction. Inthe conductive film, since the plurality of adhesive film pieces aredisposed at the end portion of the release film in the width direction,it is possible to easily attach the adhesive film piece to the adhesivesurface even when there is no enough space at one side of the adhesivesurface.

In the conductive film, the plurality of adhesive film pieces may bealso arranged in the width direction of the release film. In theconductive film, since the plurality of adhesive film pieces are alsoarranged in the width direction of the release film, it is possible toincrease the density of the adhesive film piece with respect to therelease film. Accordingly, it is possible to provide more adhesive filmpieces on the release film.

In the conductive film, a gap of the plurality of adhesive film piecesin the longitudinal direction of the release film may be 0.1 mm or moreand 10 mm or less. In the conductive film, since a gap of the pluralityof adhesive film pieces in the longitudinal direction of the releasefilm is 0.1 mm or more, it is possible to easily attach the adhesivefilm piece to the adhesive surface without affecting the near adhesivefilm piece. Meanwhile, since the gap is 10 mm or less, it is possible toincrease the density of the adhesive film piece with respect to therelease film and to provide more adhesive film pieces on the releasefilm.

In the conductive film, a gap between an end edge of the release filmand the adhesive film piece closest to the end edge in the widthdirection of the release film may be 0.1 mm or more and 10 mm or less.In the conductive film, since a gap between an end edge of the releasefilm and the adhesive film piece closest to the end edge in the widthdirection of the release film is 0.1 mm or more, it is possible toprevent the adhesive film piece from being released from the releasefilm even when the end portion of the release film interferes with theother members. Meanwhile, since the gap is 10 mm or less, it is possibleto efficiently provide the adhesive film piece on the release film.

Incidentally, there is a need to specify the position of the adhesivefilm piece in the conductive film at the time of attaching the adhesivefilm piece to the adhesive surface with high accuracy. Here, a method ofdetecting the position of the adhesive film piece in the conductive filmby the imaging device is considered. However, it is preferable todispose the imaging device at the opposite side of the adhesive filmpiece with respect to the release film when considering the attachmentof the adhesive film piece with respect to the adhesive surface later.Here, in the conductive film, the release film may have lighttransmittance. In the conductive film, since the release film has lighttransmittance, it is possible to detect the position of the adhesivefilm piece in the conductive film by the imaging device even when theimaging device is disposed at the opposite side of the adhesive filmpiece with respect to the release film.

In the conductive film, transmittance of the release film may be 15% ormore and 100% or less. In the conductive film, since the transmittanceof the release film is 15% or more, it is possible to easily detect theposition of the adhesive film piece from the release film. Meanwhile,since the transmittance of the release film is 100% or less, it ispossible to easily manufacture the release film.

In the conductive film, a haze value of the release film may be 3% ormore and 100% or less. In the conductive film, since the haze value ofthe release film is 3% or more, it is possible to easily detect theposition of the adhesive film piece from the release film. Meanwhile,since the haze value of the release film is 100% or less, it is possibleto easily manufacture the release film.

The conductive film may further include a second release film piecewhich is provided on the adhesive film piece. In the conductive film,since the surface of the adhesive film piece is covered with the secondrelease film piece, it is possible to protect the adhesive film piece.For this reason, for example, when the conductive film is wound as thewound body, it is possible to prevent the adhesive film piece from beingtransferred to the release film adjacent to the inner peripheral side orthe outer peripheral side.

In the conductive film, the adhesive film piece may be formed such thatconductive particles are dispersed in an adhesive. In the conductivefilm, since the adhesive film piece is formed such that conductiveparticles are dispersed in the adhesive, the conductive film can haveanisotropic conductivity.

A wound body according to an aspect of the invention includes: any oneof the above-described conductive films and a core on which theconductive film is wound.

In the wound body, since any one of the above-described conductive filmsis wound on the core, it is possible to attach the adhesive film pieceto the adhesive surfaces having various shapes and to efficiently usethe adhesive film piece.

A connection structure according to an aspect of the invention includes:a first circuit member that includes a first adhesive surface; a secondcircuit member that includes a second adhesive surface; and any one ofthe above-described adhesive film pieces which connect the firstadhesive surface and the second adhesive surface.

In the connection structure, the first adhesive surface and the secondadhesive surface are connected by any one of the above-describedadhesive film pieces. For this reason, it is possible to obtain theconnection structure in which the adhesive film piece is appropriatelyattached to the first adhesive surface and the second adhesive surfaceregardless of the shapes of the first adhesive surface and the secondadhesive surface.

A connection structure manufacturing method according to an aspect ofthe invention includes: a film manufacturing step of manufacturing aconductive film in which a plurality of conductive adhesive film piecesare provided on an elongated release film and the plurality of adhesivefilm pieces are arranged in a longitudinal direction of the releasefilm; and a connection step of connecting a first adhesive surface of afirst circuit member and a second adhesive surface of a second circuitmember with the adhesive film piece of the conductive film interposedtherebetween.

In the connection structure manufacturing method, the conductive film inwhich the plurality of adhesive film pieces are provided on the releasefilm is manufactured and the first adhesive surface and the secondadhesive surface are connected with the adhesive film piece of theconductive film interposed therebetween. Then, since the adhesive filmpiece can be set to an arbitrary shape, it is possible to manufacturethe connection structure in which the adhesive film piece isappropriately attached to the first adhesive surface and the secondadhesive surface regardless of the shapes of the first adhesive surfaceand the second adhesive surface. Further, it is possible to efficientlyuse the adhesive film piece.

In the connection structure manufacturing method, the adhesive filmpiece may be formed such that conductive particles are dispersed in anadhesive. In the connection structure manufacturing method, the adhesivefilm piece is formed such that conductive particles are dispersed in theadhesive, the adhesive film piece can have anisotropic conductivity.

In the connection structure manufacturing method, the film manufacturingstep may include an adhesive film layer forming step of forming aconductive adhesive film layer on an entire surface of the release film,an adhesive film layer cutting step of cutting the adhesive film layeralong an outline forming an outer shape of the adhesive film piece, anda margin releasing step of releasing a margin portion corresponding to aportion other than the adhesive film piece in the adhesive film layerfrom the release film along the cut outline. In the connection structuremanufacturing method, the adhesive film layer is formed on the entiresurface of the release film, the adhesive film layer is cut along theoutline, and the margin portion is released from the release film alongthe cut outline. Accordingly, it is possible to easily provide theplurality of adhesive film pieces on the release film.

In the connection structure manufacturing method, the adhesive filmlayer may be formed such that conductive particles are dispersed in theadhesive. In the connection structure manufacturing method, since theadhesive film layer is formed such that conductive particles aredispersed in the adhesive, the adhesive film piece obtained by cuttingthe adhesive film layer can have anisotropic conductivity.

In the connection structure manufacturing method, the connection stepmay include a position detecting step of detecting a position of theadhesive film piece in the conductive film by an imaging device, anattachment step of attaching the adhesive film piece to the firstadhesive surface on the basis of the position detected by the positiondetecting step, and an overlapping step of overlapping the firstadhesive surface and the second adhesive surface with the adhesive filmpiece interposed therebetween. In the connection structure manufacturingmethod, the position of the adhesive film piece in the conductive filmis detected by the imaging device and the adhesive film piece isattached to the first adhesive surface on the basis of the detectedposition. For this reason, it is possible to improve the positionaccuracy of the adhesive film piece with respect to the adhesivesurface. Then, since the first adhesive surface and the second adhesivesurface are overlapped with the adhesive film piece interposedtherebetween, it is possible to easily accommodate the adhesive filmpiece in the first adhesive surface and the second adhesive surface.

In the connection structure manufacturing method, the conductive filmmay be manufactured such that a second release film piece is provided onthe adhesive film piece in the film manufacturing step. In theconnection structure manufacturing method, since the surface of theadhesive film piece is covered with the second release film piece, it ispossible to protect the adhesive film piece. For this reason, forexample, when the conductive film is wound as the wound body, it ispossible to prevent the adhesive film piece from being transferred tothe release film adjacent to the inner peripheral side or the outerperipheral side.

In the connection structure manufacturing method, the film manufacturingstep may include an adhesive film layer forming step of forming aconductive adhesive film layer on an entire surface of the release filmand covering an entire surface of the adhesive film layer with a secondrelease film, an adhesive film layer cutting step of cutting theadhesive film layer and the second release film along an outline formingan outer shape of the adhesive film piece, and a margin releasing stepof releasing a margin portion corresponding to a portion other than theadhesive film piece in the adhesive film layer and the second releasefilm from the release film along the cut outline. In the connectionstructure manufacturing method, the adhesive film layer is formed on theentire surface of the release film, the entire surface of the adhesivefilm layer is covered with the second release film, the adhesive filmlayer is cut along the outline, and the margin portion is released fromthe release film along the cut outline. Accordingly, it is possible toeasily provide the plurality of adhesive film pieces on the release filmand to cover the adhesive film piece with the second release film piece.

In the connection structure manufacturing method, the adhesive filmlayer may be formed such that conductive particles are dispersed in theadhesive. In the connection structure manufacturing method, since theadhesive film layer is formed such that conductive particles aredispersed in the adhesive, the adhesive film piece which is obtained bycutting the adhesive film layer can have anisotropic conductivity.

In the connection structure manufacturing method, the connection stepmay include a position detecting step of detecting a position of theadhesive film piece in the conductive film by an imaging device, anattachment step of attaching the adhesive film piece to the firstadhesive surface on the basis of the position detected by the positiondetecting step, an overlapping step of overlapping the first adhesivesurface and the second adhesive surface with the adhesive film pieceinterposed therebetween, and a second release film piece releasing stepof releasing the second release film piece from the adhesive film piecebefore the attachment step. In the connection structure manufacturingmethod, the position of the adhesive film piece in the conductive filmis detected by the imaging device and the adhesive film piece isattached to the first adhesive surface on the basis of the detectedposition. For this reason, it is possible to improve the positionaccuracy of the adhesive film piece with respect to the adhesivesurface. Then, since the first adhesive surface and the second adhesivesurface are overlapped with the adhesive film piece interposedtherebetween, it is possible to easily accommodate the adhesive filmpiece in the first adhesive surface and the second adhesive surface.Then, since the second release film piece is released from the adhesivefilm piece before the attachment step, it is possible to reliably attachthe adhesive film piece to the first adhesive surface.

In the connection structure manufacturing method, the adhesive filmpiece may be attached to the first adhesive surface and then the releasefilm may be released from the adhesive film piece in the attachmentstep. In the connection structure manufacturing method, since theadhesive film piece is attached to the first adhesive surface and thenthe release film is released from the adhesive film piece, it ispossible to easily attach the adhesive film piece to the first adhesivesurface.

In the connection structure manufacturing method, the connection stepmay further include a film cutting step of cutting the conductive filminto a plurality of conductive film pieces in which one or the pluralityof adhesive film pieces are provided in the release film before theposition detecting step and in the position detecting step, the positionof the adhesive film piece of the conductive film piece may be detectedby the imaging device. In the connection structure manufacturing method,since the conductive film is cut into the plurality of conductive filmpieces, it is possible to flexibly handle a case in which the adhesivefilm piece is attached to a plurality of positions or the attachmentdirection of the adhesive film piece needs to be changed. Then, sincethe position of the adhesive film piece of the conductive film piece isdetected by the imaging device, it is possible to improve the positionaccuracy of the adhesive film piece with respect to the adhesive surfaceeven when the conductive film is cut into a plurality of conductive filmpieces.

Advantageous Effects of Invention

According to the invention, it is possible to attach the adhesive filmto adhesive surfaces having various shapes and to efficiently use theadhesive film.

Possible.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating a wound body according to anembodiment.

FIG. 2 is a plan view illustrating an anisotropic conductive filmaccording to the embodiment.

FIG. 3 is a cross-sectional view taken along a line III-III of FIG. 2 .

FIG. 4 is a plan view illustrating a position of an adhesive film piecewith respect to a release film.

FIG. 5 is a cross-sectional view illustrating a connection structureaccording to the embodiment.

FIG. 6 is a flowchart illustrating a connection structure manufacturingmethod according to the embodiment.

FIG. 7 is a flowchart illustrating a film manufacturing step illustratedin FIG. 6 .

FIGS. 8(a), 8(b), 8(c), and 8(d) are cross-sectional views illustratingthe film manufacturing step illustrated in FIG. 6 .

FIGS. 9(a), 9(b), 9(c), and 9(d) are perspective views illustrating thefilm manufacturing step illustrated in FIG. 6 .

FIG. 10 is a flowchart illustrating a connection step illustrated inFIG. 6 .

FIG. 11 is a schematic process diagram illustrating the connection stepillustrated in FIG. 6 .

FIG. 12 is a plan view illustrating an anisotropic conductive film of amodified example.

FIGS. 13(a), 13(b), and 13(c) are plan views illustrating anisotropicconductive films of modified examples.

FIGS. 14(a), 14(b), and 14(c) are plan views illustrating anisotropicconductive films of modified examples.

FIG. 15 is a plan view illustrating anisotropic conductive films ofmodified examples.

FIG. 16 is a plan view illustrating an anisotropic conductive film of amodified example.

FIGS. 17(a), 17(b), and 17(c) are plan views illustrating anisotropicconductive films of modified examples.

FIGS. 18(a), 18(b), and 18(c) are plan views illustrating anisotropicconductive films of modified examples.

FIG. 19 is a cross-sectional view illustrating an anisotropic conductivefilm of a first modified example.

FIGS. 20(a), 20(b), 20(c), 20(d), and 20(e) are cross-sectional viewsillustrating a film manufacturing step in an anisotropic conductive filmmanufacturing method of the first modified example.

FIG. 21 is a flowchart illustrating a connection step of a connectionstructure manufacturing method of a second modified example.

FIG. 22 is a schematic process diagram illustrating the connection stepillustrated in FIG. 21 .

FIG. 23 is a plan view illustrating a film cutting step illustrated inFIG. 21 .

DESCRIPTION OF EMBODIMENTS

Hereinafter, preferred embodiments of the invention will be described indetail with reference to the drawings. In the embodiment, a conductivefilm according to the invention is applied to an anisotropic conductivefilm having anisotropic conductivity. However, the conductive filmaccording to the invention can be also applied to various conductivefilms not having anisotropic conductivity. Additionally, in thedrawings, the same or equivalent components are indicated by the samereference numerals and a redundant description thereof is omitted.Further, a dimensional ratio and the like are appropriately changed inorder to easily understand the drawings.

[Wound Body]

As illustrated in FIG. 1 , a wound body 1 includes an elongated(tape-like) anisotropic conductive film 2 and a core 3 on which theanisotropic conductive film 2 is wound. That is, the wound body 1 isobtained such that the anisotropic conductive film 2 is wound on thecore 3.

The core 3 includes a core material 3 a and a pair of side plates 3 b.The core material 3 a is formed in a columnar shape. The anisotropicconductive film 2 is wound on the outer peripheral surface of the corematerial 3 a. The pair of side plates 3 b is attached to both endportions of the core material 3 a in the axial direction. The pair ofside plates 3 b supports the anisotropic conductive film 2 from theright and left sides. A gap of the pair of side plates 3 b is slightlywider than the width of the anisotropic conductive film 2

[Anisotropic Conductive Film]

As illustrated in FIGS. 1 to 3 , the anisotropic conductive film 2includes an elongated (tape-like) release film 4 and a plurality ofconductive adhesive film pieces 5 which are provided on the release film4. In the adhesive film piece 5, conductive particles 7 are dispersed inthe adhesive 6 in order to have conductivity. Additionally, the outershape of the anisotropic conductive film 2 is defined by the outer shapeof the release film 4 in plan view.

The release film 4 is attached to the adhesive film piece 5 and supportsthe adhesive film piece 5. As the material of the release film 4, forexample, polyethylene terephthalate (PET), polyethylene, polypropylene,or the like can be used. The release film 4 may contain any filler.Further, the surface of the release film 4 may be subjected to a releasetreatment, a plasma treatment, and the like.

Incidentally, there is a need to specify the position of the adhesivefilm piece 5 of the anisotropic conductive film 2 at the time ofattaching the adhesive film piece 5 to an adhesive surface (notillustrated) of an adhering target (not illustrated) with high accuracy.Here, a method of detecting the position of the adhesive film piece 5 ofthe anisotropic conductive film 2 by an imaging device 21 (see FIG. 11 )is considered. However, it is preferable to dispose the imaging device21 at the opposite side of the adhesive film piece 5 with respect to therelease film 4 when considering the attachment of the adhesive filmpiece 5 with respect to the adhesive surface later.

Here, the release film 4 may have light transmittance in order to detectthe position of the adhesive film piece 5 from the release film 4 by theimaging device 21.

In this case, the transmittance of the release film 4 can be set to 15%or more and 100% or less, is preferably 15% or more and 99% or less, andis more preferably 16% or more and 98% or less.

The transmittance of the release film 4 can be measured as below. Arelease film cut into a square size of 50 mm×50 mm is set in a hazemeter (for example, NDH-5000 manufactured by Nippon Denshoku Kogyo Co.,Ltd.) and the total light transmittance is measured. Then, thismeasurement result is set to the transmittance of the release film 4.

Further, the haze value of the release film 4 can be set to 3% or moreand 100% or less, is preferably 3% or more and 99% or less, and is morepreferably 4% or more and 99% or less.

The haze value of the release film 4 can be measured as below. A releasefilm cut into a square size of 50 mm×50 mm is set in a haze meter (forexample, NDH-5000 manufactured by Nippon Denshoku Kogyo Co., Ltd.) andthe haze value is measured. Then, this measurement result is set as thehaze value of the release film 4.

As the adhesive 6 constituting the adhesive film piece 5, for example,thermoplastic resin, thermosetting resin, a mixed material ofthermoplastic resin and thermosetting resin, and photocurable resin areused. As the thermoplastic resin, for example, styrene resin andpolyester resin are used. As the thermosetting resin, for example, epoxyresin and silicone resin are used. When the thermoplastic resin and thethermosetting resin, a heating/pressing operation is generally required.There is a need to flow the resin to obtain adhesion with an adheringobject in the thermoplastic resin and to carry out a curing reaction ofthe resin in the thermosetting resin. Further, since the photocurableresin does not require a heating operation for curing, the photocurableresin is useful when a low-temperature connection is required.

As the conductive particles 7 constituting the adhesive film piece 5,for example, metallic particles such as Au, Ag, Ni, Cu, Pd, and solderand carbon particles are used. Further, the conductive particles 7 maybe obtained by covering the surface of transition metal such as Ni or Cuwith noble metal such as Au or Pd. Further, the conductive particles 7may have a conductive layer formed on the surface of the non-conductiveparticle by a method of covering the surfaces of the nonconductiveparticles such as glass, ceramic, or plastic with a conductive material.The conductive particles 7 may be those in which the outermost layer isformed of noble metal or those which use heat melting metal particles.

The plurality of adhesive film pieces 5 are arranged in the longitudinaldirection X of the release film 4. The longitudinal direction X of therelease film 4 indicates a direction in which the anisotropic conductivefilm 2 is unwound from the wound body 1.

Here, the plurality of adhesive film pieces 5 may be spaced in thelongitudinal direction X of the release film 4 or may be connected inthe longitudinal direction X of the release film 4. As illustrated inFIG. 2 , in the embodiment, the plurality of adhesive film pieces 5 arespaced in the longitudinal direction X of the release film 4. However,the plurality of adhesive film pieces 5 may be connected in thelongitudinal direction X of the release film 4 similarly to ananisotropic conductive film 2A illustrated in FIG. 12 .

Further, the shape of the adhesive film piece 5 is not particularlylimited and can be set to various shapes. As illustrated in FIG. 2 , inthe embodiment, the adhesive film piece 5 is formed in a circular shape.However, the adhesive film piece 5 may be formed in an oval shape as inan anisotropic conductive film 2B1 illustrated in FIG. 13(a) or anelongated linear shape as in an anisotropic conductive film 2C1illustrated in FIG. 14(a). In such a case, the adhesive film piece 5 mayextend in a direction orthogonal to the longitudinal direction X of therelease film 4 as in the anisotropic conductive film 2B1 illustrated inFIG. 13(a) and the anisotropic conductive film 2C1 illustrated in FIG.14(a), may extend in a direction parallel to the longitudinal directionX of the release film 4 as in an anisotropic conductive film 2B2illustrated in FIG. 13(b) and an anisotropic conductive film 2C2illustrated in FIG. 14(b), and may extend in a direction inclined withrespect to the longitudinal direction X of the release film 4 as in ananisotropic conductive film 2B3 illustrated in FIG. 13(c) and ananisotropic conductive film 2C3 illustrated in FIG. 14(c).

Further, the adhesive film piece 5 may be provided with a hole. Asillustrated in FIG. 2 , in the embodiment, the adhesive film piece 5 isnot provided with a hole. However, a hole 5 a may be formed in theadhesive film piece 5 as in an anisotropic conductive film 2G1illustrated in FIG. 18(a), an anisotropic conductive film 2G2illustrated in FIG. 18(b), and an anisotropic conductive film 2G3illustrated in FIG. 18(c). The hole 5 a is formed by punching out(perforating) a part of the adhesive film piece 5. The shape, size,position, number, and the like of the hole 5 a are not particularlylimited. For example, the hole 5 a may be similar to the adhesive filmpiece 5 or may not be similar to the adhesive film piece 5. As the shapeof the hole 5 a, a circle such as a perfect circle and an ellipse, apolygon such as a triangle and a quadrilateral, a star shape, and acomplicated shape such as various marks can be exemplified. Examples ofthe square include a square, a rectangle, and a trapezoid. The positionof the hole 5 a may be the center portion of the adhesive film piece 5or the end portion of the adhesive film piece 5. The number of the holes5 a formed in one adhesive film piece 5 may be one or two or more. Whena plurality of the holes 5 a are formed in one adhesive film piece 5,the shapes, sizes, and the like of the holes 5 a may be the same ordifferent. In the anisotropic conductive film 2G1 illustrated in FIG.18(a), a square hole 5 a similar to the adhesive film piece 5 is formedat the center portion of the adhesive film piece 5 having a square outershape. In the anisotropic conductive film 2G2 illustrated in FIG. 18(b),a circular hole 5 a similar to the adhesive film piece 5 is formed atthe center portion of the adhesive film piece 5 having a circular outershape. In the anisotropic conductive film 2G3 illustrated in FIG. 18(c),a circular square hole 5 a is formed at the center portion of theadhesive film piece 5 having a square outer shape.

Further, the plurality of adhesive film pieces 5 may have the same shapeor different shapes. As illustrated in FIG. 2 , in the embodiment, allof the plurality of adhesive film pieces 5 have the same shape. However,the plurality of adhesive film pieces 5 may have different shapes as inan anisotropic conductive film 2D illustrated in FIG. 15 . In this case,all adhesive film pieces 5 may have different shapes or the adhesivefilm pieces 5 having different shapes and the adhesive film pieces 5having the same shape may exist together.

Further, the plurality of adhesive film pieces 5 may be disposed at anyposition in the width direction Y of the release film 4. The widthdirection Y of the release film 4 indicates a direction orthogonal tothe longitudinal direction X of the release film 4 and the thicknessdirection Z of the release film 4 (see FIG. 3 ). For example, asillustrated in FIG. 2 , in the embodiment, the adhesive film piece 5 isdisposed on the center portion in the width direction Y of the releasefilm 4. However, the adhesive film piece 5 may be disposed at the endportion in the width direction Y of the release film 4 as in ananisotropic conductive film 2E illustrated in FIG. 16 .

Further, the plurality of adhesive film pieces 5 may be arranged as onerow in the width direction of the release film 4 or may be arranged as aplurality of rows in the width direction of the release film 4. Asillustrated in FIG. 2 , in the embodiment, the plurality of adhesivefilm pieces 5 are arranged as one row in the width direction of therelease film 4. However, the plurality of adhesive film pieces 5 may bearranged as two rows in the width direction of the release film 4 as inan anisotropic conductive film 2F1 illustrated in FIG. 17(a), may bearranged as three rows in the width direction of the release film 4 asin an anisotropic conductive film 2F2 illustrated in FIG. 17(b), or maybe arranged such that the number of arrangements in the width directionof the release film 4 is different in the longitudinal direction of therelease film 4 as in an anisotropic conductive film 2F3 illustrated inFIG. 17(c).

Further, the plurality of adhesive film pieces 5 spaced in thelongitudinal direction X of the release film 4 may be arranged at anon-overlapping position or an overlapping position when viewed from thewidth direction Y of the release film 4. As illustrated in FIG. 2 , inthe embodiment, the plurality of adhesive film pieces 5 spaced in thelongitudinal direction X of the release film 4 are arranged at anon-overlapping position when viewed from the width direction Y of therelease film 4. However, the plurality of adhesive film pieces 5 spacedin the longitudinal direction X of the release film 4 may be arranged atan overlapping position when viewed from the width direction Y of therelease film 4 as in the anisotropic conductive film 2B3 illustrated inFIG. 13(c) and the anisotropic conductive film 2C3 illustrated in FIG.14(c).

As illustrated in FIG. 4 , a gap A of the plurality of adhesive filmpieces 5 in the longitudinal direction X of the release film 4 can beset to 0.1 mm or more and 10 mm or less, is preferably 0.1 mm or moreand 0.8 mm or less, and is more preferably 0.2 mm or more and 0.5 mm orless. Further, a gap B between an end edge of the release film 4 and theadhesive film piece 5 closest to the end edge in the width direction Yof the release film 4 can be set to 0.1 mm or more and 10 mm or less, ispreferably 0.1 mm or more and 0.8 mm or less, and is more preferably 0.2mm or more and 0.5 mm or less.

[Connection Structure]

As illustrated in FIG. 5 , the connection structure 10 includes a firstcircuit member 11 that includes a first adhesive surface 11 a, a secondcircuit member 12 that includes a second adhesive surface 12 a, and theadhesive film piece 5 which connects the first adhesive surface 11 a andthe second adhesive surface 12 a to each other.

The first circuit member 11 is, for example, a chip component such as anIC chip, an LSI chip, a resistor chip, or a capacitor chip. A surfacefacing the second circuit member 12 in the first circuit member 11becomes the first adhesive surface 11 a. A first electrode (notillustrated) which is used to be electrically connected to the secondcircuit member 12 is disposed on the first adhesive surface 11 a.

The second circuit member 12 is, for example, a substrate having lighttransmittance such as a glass substrate, a polyimide substrate, apolyethylene terephthalate substrate, a polycarbonate substrate, acycloolefin polymer (COP) substrate, a polyethylene naphthalatesubstrate, a glass reinforced epoxy substrate, a paper phenol substrate,a ceramic substrate, and a laminate plate. In the second circuit member12, a surface facing the first adhesive surface 11 a of the firstcircuit member 11 becomes the second adhesive surface 12 a. A secondelectrode (not illustrated) which is electrically connected to the firstcircuit member 11 is disposed on the second adhesive surface 12 a.

Additionally, there is no clear distinction between the first circuitmember 11 and the second circuit member 12 and any member may be appliedto each circuit member. As the first circuit member 11, for example, asubstrate having light transmittance such as a glass substrate, apolyimide substrate, a polyethylene terephthalate substrate, apolycarbonate substrate, a cycloolefin polymer (COP) substrate, apolyethylene naphthalate substrate, a glass reinforced epoxy substrate,a paper phenol substrate, a ceramic substrate, and a laminate plate maybe used. Further, as the second circuit member 12, for example, a chipcomponent such as an IC chip, an LSI chip, a resistor chip, or acapacitor chip may be used.

The adhesive film piece 5 is the adhesive film piece 5 which is releasedfrom the anisotropic conductive film 2. In the adhesive film piece 5,the first adhesive surface 11 a is connected to the second adhesivesurface 12 a by the adhesive 6 and the first electrode of the firstadhesive surface 11 a is electrically connected to the second electrodeof the second adhesive surface 12 a by the conductive particles 7dispersed in the adhesive 6.

[Connection Structure Manufacturing Method]

As illustrated in FIG. 6 , the connection structure manufacturing methodincludes a film manufacturing step (S1) and a connection step (S2)performed after the film manufacturing step (S1).

In the film manufacturing step (S1), the anisotropic conductive film 2in which the plurality of conductive adhesive film pieces 5 are providedon the elongated release film 4 and the plurality of adhesive filmpieces 5 are arranged in the longitudinal direction of the release film4 is manufactured. The adhesive film piece 5 is one in which theconductive particles 7 are dispersed in the adhesive 6 in order to haveanisotropic conductivity. In the connection step (S2), the firstadhesive surface 11 a of the first circuit member 11 is connected to thesecond adhesive surface 12 a of the second circuit member 12 through theadhesive film piece 5 of the anisotropic conductive film 2.

As illustrated in FIG. 7 , the film manufacturing step (S1) includes anadhesive film layer forming step (S11), an adhesive film layer cuttingstep (S12) performed after the adhesive film layer forming step (S1),and a margin releasing step (S13) performed after the adhesive filmlayer cutting step (S12).

In the adhesive film layer forming step (S11), as illustrated in FIGS.8(a) and 9(a), the release film 4 is first prepared. Then, asillustrated in FIGS. 8(b) and 9(b), a conductive adhesive film layer 5Ais formed on an entire surface of the release film 4. The adhesive filmlayer 5A is one in which the conductive particles 7 are dispersed in theadhesive 6. The adhesive 6 and the conductive particles 7 constitutingthe adhesive film layer 5A are the same as the adhesive 6 and theconductive particles 7 constituting the adhesive film piece 5.

In the adhesive film layer cutting step (S12), as illustrated in FIGS.8(c) and 9(c), the adhesive film layer 5A formed on the release film 4is cut along an outline 5B forming the outer shape of the adhesive filmpiece 5. Accordingly, the adhesive film layer 5A is divided into aninner portion 5A1 which is located at the inside of the outline 5B and aplurality of margin portions 5A2 which are located at the outside of theoutline 5B. The inner portion 5A1 is a portion which becomes theadhesive film piece 5. The margin portion 5A2 is a portion which becomesa portion other than the adhesive film piece 5. For example, theadhesive film layer 5A is cut in such a manner that the adhesive filmlayer 5A is pressed against a cutter having a cutting blade formed onthe outer peripheral surface thereof. Accordingly, even when theadhesive film piece 5 has a complex shape, a fine shape, or the like,the adhesive film layer 5A can be easily cut along the outline 5B.

In the margin releasing step (S13), as illustrated in FIGS. 8(d) and9(d), the margin portion 5A2 corresponding to a portion other than theadhesive film piece 5 in the adhesive film layer 5A is released from therelease film 4 along the cut outline 5B. For example, the margin portion5A2 is released in such a manner that an adhesive tape is attached tothe margin portion 5A2 and the adhesive tape is pulled out so that themargin portion 5A2 is released from the release film 4. Then, the innerportion 5A1 which remains on the release film 4 becomes the adhesivefilm piece 5. Accordingly, the anisotropic conductive film 2 in whichthe plurality of adhesive film pieces 5 are provided on the release film4 is manufactured.

The anisotropic conductive film 2 which is manufactured in this way isaccommodated and carried as the wound body 1 in which the anisotropicconductive film is wound on the core 3 and is taken over to theconnection step (S2). Additionally, the anisotropic conductive film 2may be taken over to the connection step (S2) while not being wound asthe wound body 1.

As illustrated in FIG. 10 , the connection step (S2) includes a positiondetecting step (S21), an attachment step (S22), and an overlapping step(S23).

In the position detecting step (S21), the anisotropic conductive film 2is first unwound from the wound body 1. Then, as illustrated in FIG. 11, the position of the adhesive film piece 5 of the anisotropicconductive film is detected by the imaging device 21. At this time, theimaging device 21 may be disposed at the side of the adhesive film piece5 with respect to the release film 4 or may be disposed at the oppositeside of the adhesive film piece 5 with respect to the release film 4. Asillustrated in FIG. 11 , in the embodiment, the imaging device 21 isdisposed at the opposite side of the adhesive film piece 5 with respectto the release film 4. In this case, the imaging device 21 can detectthe position of the adhesive film piece 5 of the anisotropic conductivefilm 2 from the release film 4 by using the release film 4 having lighttransmittance.

In the attachment step (S22), the adhesive film piece 5 is attached tothe first adhesive surface 11 a on the basis of the position detected bythe position detecting step (S21). Subsequently, the release film 4 isreleased from the adhesive film piece 5 attached to the first adhesivesurface 11 a.

In the overlapping step (S23), the first adhesive surface 11 a and thesecond adhesive surface 12 a are overlapped with the adhesive film piece5 interposed therebetween. Accordingly, the first adhesive surface 11 aand the second adhesive surface 12 a are temporarily connected by theadhesive 6 of the adhesive film piece 5. Then, the first circuit member11 and the second circuit member 12 are pressed so that the firstcircuit member 11 is electrically connected to the second circuit member12 by the conductive particles 7 of the adhesive film piece 5 and theadhesive 6 of the adhesive film piece 5 is heated or irradiated withlight to cure the adhesive 6. Accordingly, it is possible to obtain theconnection structure 10 in which the first adhesive surface 11 a and thesecond adhesive surface 12 a are connected to each other by the adhesivefilm piece 5.

In this way, in the anisotropic conductive film 2 according to theembodiment, the plurality of adhesive film pieces 5 are arranged on theelongated release film 4 in the longitudinal direction X of the releasefilm 4. For this reason, the adhesive film piece 5 can be set to anarbitrary shape. Accordingly, it is possible to attach the adhesive filmpiece 5 to adhesive surfaces having various shapes and to efficientlyuse the adhesive film piece 5.

Further, in the anisotropic conductive film 2, when the plurality ofadhesive film pieces 5 are spaced in the longitudinal direction X of therelease film 4, it is possible to attach the adhesive film piece 5 tothe adhesive surface without affecting the near adhesive film piece 5.Accordingly, it is possible to easily attach the adhesive film piece 5to the adhesive surface. Further, it is possible to further improve adegree of freedom in the shape of the adhesive film piece 5.

Further, in the anisotropic conductive film 2, when the plurality ofadhesive film pieces 5 have the same shape, it is possible toefficiently attach the adhesive film piece 5 to a plurality of adhesivesurfaces having the same shape.

Further, in the anisotropic conductive film 2, when the plurality ofadhesive film pieces 5 are disposed at the center portion of the widthdirection of the release film 4, it is possible to easily position theanisotropic conductive film 2 with respect to the adhesive surface atthe time of attaching the adhesive film piece 5 to the adhesive surface.

Further, in the anisotropic conductive film 2, when the plurality ofadhesive film pieces 5 are disposed at the end portion of the widthdirection of the release film 4, it is possible to easily attach theadhesive film piece 5 to the adhesive surface even when there is noenough space at one side of the adhesive surface.

Further, in the anisotropic conductive film 2, when the plurality ofadhesive film pieces 5 are arranged in the width direction Y of therelease film 4, it is possible to increase the density of the adhesivefilm piece 5 with respect to the release film 4. Accordingly, it ispossible to provide more adhesive film pieces 5 on the release film 4.

Further, in the anisotropic conductive film 2, when a gap of theplurality of adhesive film pieces 5 in the longitudinal direction X ofthe release film 4 is 0.1 mm or more, it is possible to easily attachthe adhesive film piece 5 to the adhesive surface without affecting thenear adhesive film piece 5. Meanwhile, when the gap is 10 mm or less, itis possible to increase the density of the adhesive film piece 5 withrespect to the release film 4 and to provide more adhesive film pieces 5on the release film 4.

Further, in the anisotropic conductive film 2, when a gap between theend edge of the release film 4 and the adhesive film piece 5 closest tothe end edge in the width direction of the release film 4 is 0.1 mm ormore, it is possible to prevent the adhesive film piece 5 from beingreleased from the release film 4 even when the end portion of therelease film 4 interferes with the other members. Meanwhile, when thegap is 10 mm or less, it is possible to efficiently provide the adhesivefilm piece 5 on the release film 4.

Further, in the anisotropic conductive film 2, when the release film 4has light transmittance, it is possible to detect the position of theadhesive film piece 5 of the anisotropic conductive film 2 by theimaging device 21 even when the imaging device 21 is disposed at theopposite side of the adhesive film piece 5 with respect to the releasefilm 4.

Further, in the anisotropic conductive film 2, when the transmittance ofthe release film 4 is 15% or more, it is possible to easily detect theposition of the adhesive film piece 5 from the release film 4.Meanwhile, when the transmittance of the release film 4 is 100% or less,it is possible to easily manufacture the release film 4.

Further, in the anisotropic conductive film 2, when the haze value ofthe release film 4 is 3% or more, it is possible to easily detect theposition of the adhesive film piece 5 from the release film 4.Meanwhile, when the haze value of the release film 4 is 100% or less, itis possible to easily manufacture the release film 4.

In the wound body 1 according to the embodiment, since the anisotropicconductive film 2 is wound on the core 3, it is possible to attach theadhesive film piece 5 to adhesive surfaces having various shapes and toefficiently use the adhesive film piece 5.

In the connection structure 10 according to the embodiment, the firstadhesive surface 11 a and the second adhesive surface 12 a are connectedto each other by the adhesive film piece 5. For this reason, it ispossible to obtain the connection structure 10 in which the adhesivefilm piece 5 is appropriately attached to the first adhesive surface 11a and the second adhesive surface 12 a regardless of the shapes of thefirst adhesive surface 11 a and the second adhesive surface 12 a.

In the connection structure manufacturing method according to theembodiment, the anisotropic conductive film 2 in which the plurality ofadhesive film pieces 5 are provided on the release film 4 ismanufactured and the first adhesive surface 11 a and the second adhesivesurface 12 a are connected with the adhesive film piece 5 of theanisotropic conductive film 2 interposed therebetween. Then, since theadhesive film piece 5 can be set to an arbitrary shape, it is possibleto manufacture the connection structure 10 in which the adhesive filmpiece 5 is appropriately attached to the first adhesive surface 11 a andthe second adhesive surface 12 a regardless of the shapes of the firstadhesive surface 11 a and the second adhesive surface 12 a. Further, itis possible to efficiently use the adhesive film piece 5.

Further, in the connection structure manufacturing method, the adhesivefilm layer 5A is formed on an entire surface of the release film 4, theadhesive film layer 5A is cut along the outline 5B, and the marginportion 5A2 is released from the release film 4 along the cut outline5B. Accordingly, it is possible to easily provide the plurality ofadhesive film pieces 5 on the release film 4.

Further, in the connection structure manufacturing method, the positionof the adhesive film piece 5 of the anisotropic conductive film 2 isdetected by the imaging device 21 and the adhesive film piece 5 isattached to the first adhesive surface 11 a on the basis of the detectedposition. For this reason, it is possible to improve the positionaccuracy of the adhesive film piece 5 with respect to the adhesivesurface. Then, since the first adhesive surface 11 a and the secondadhesive surface 12 a are overlapped with the adhesive film piece 5interposed therebetween, it is possible to easily accommodate theadhesive film piece 5 in the first adhesive surface 11 a and the secondadhesive surface 12 a.

Further, in the connection structure manufacturing method, since therelease film 4 is released from the adhesive film piece 5 after theadhesive film piece 5 is attached to the first adhesive surface 11 a, itis possible to easily attach the adhesive film piece 5 to the firstadhesive surface 11 a.

The invention is not limited to the above-described embodiment and canbe appropriately modified without departing from the spirit of theinvention. Hereinafter, modified examples of the above-describedembodiment will be described.

First Modified Example

As illustrated in FIG. 19 , an anisotropic conductive film 2H of a firstmodified example further includes a second release film piece 8 whichcovers the adhesive film piece 5. That is, the anisotropic conductivefilm 2H includes the elongated release film 4, the plurality of adhesivefilm pieces 5 which are provided on the release film 4 and in which theconductive particles 7 are dispersed in the adhesive 6, and the secondrelease film piece 8 which is provided on each adhesive film piece 5.The second release film piece 8 is a film which protects the adhesivefilm piece 5 by covering the surface of the adhesive film piece 5. Forthis reason, in the first modified example, the wound body 1 is formedsuch that the anisotropic conductive film 2H is wound on the core 3.

In the first modified example, the film manufacturing step (S1) and theconnection step (S2) are set as below.

In the adhesive film layer forming step (S11) of the film manufacturingstep (S1), the release film 4 is first prepared as illustrated in FIG.20(a). Next, as illustrated in FIG. 20(b), the adhesive film layer 5A isformed on an entire surface of the release film 4. Next, as illustratedin FIG. 20(c), a second release film 8A is covered (attached) on anentire surface of the adhesive film layer 5A. The material of the secondrelease film 8A is the same as that of the second release film piece 8.

In the adhesive film layer cutting step (S12) of the film manufacturingstep (S1), as illustrated in FIG. 20(d), the adhesive film layer 5A andthe second release film 8A formed on the release film 4 are cut alongthe outline 5B. Accordingly, the adhesive film layer 5A is divided intothe inner portion 5A1 which is located at the inside of the outline 5Band the plurality of margin portions 5A2 which are located at theoutside of the outline 5B. Similarly, the second release film 8A isdivided into an inner portion 8A1 which is located at the inside of theoutline 5B and a plurality of margin portions 8A2 which are located atthe outside of the outline 5B.

In the margin releasing step (S13) of the film manufacturing step (S1),as illustrated in FIG. 20(e), the margin portion 5A2 and the marginportion 8A2 are released from the release film 4 along the cut outline5B. Then, the inner portion 5A1 and the inner portion 8A1 remain on therelease film 4. The inner portion 5A1 and the inner portion 8A1 whichremain on the release film 4 become the adhesive film piece 5 and thesecond release film piece 8. Accordingly, the anisotropic conductivefilm 2H in which the plurality of adhesive film pieces 5 covered withthe second release film piece 8 are provided on the release film 4 ismanufactured.

The anisotropic conductive film 2H is accommodated and carried as thewound body 1 in which the anisotropic conductive film is wound on thecore 3 and is taken over to the connection step (S2). Additionally, theanisotropic conductive film 2H may be taken over to the connection step(S2) while not being wound as the wound body 1.

In the connection step (S2), a second release film piece releasing stepis performed before the attachment step (S22). In the releasing step,the second release film piece 8 is first released from the adhesive filmpiece 5 in the anisotropic conductive film 2H drawn out from the woundbody 1. For example, it is possible to release the second release filmpiece 8 in such a manner that an adhesive tape is attached to the secondrelease film piece 8 and the adhesive tape is pulled out so that thesecond release film piece 8 is released from the adhesive film piece 5.Additionally, the releasing step may be performed at any stage of theconnection step (S2) as long as the step is before the attachment step(S22). The subsequent steps are the same as those of the above-describedembodiment.

In this way, in the anisotropic conductive film 2H of the first modifiedexample, since the surface of the adhesive film piece 5 is covered withthe second release film piece 8, it is possible to protect the adhesivefilm piece 5. For this reason, it is possible to prevent the adhesivefilm piece 5 from being transferred to the release film 4 adjacent tothe inner peripheral side or the outer peripheral side in the wound body1 in which the anisotropic conductive film 2H is wound on the core 3.

Further, in the first modified example, the adhesive film layer 5A isformed on an entire surface of the release film 4, an entire surface ofthe adhesive film layer 5A is covered with the second release film 8A,the adhesive film layer 5A is cut along the outline 5B, and the marginportion 5A2 is released from the release film 4 along the cut outline5B. Accordingly, it is possible to easily provide the plurality ofadhesive film pieces 5 on the release film 4 and to cover the adhesivefilm piece 5 with the second release film piece 8.

Further, since the second release film piece 8 is released from theadhesive film piece 5 before the attachment step, it is possible toreliably attach the adhesive film piece 5 to the first adhesive surface11 a.

Second Modified Example

As illustrated in FIG. 21 , in a connection structure manufacturingmethod of a second modified example, the connection step (S2) furtherincludes a film cutting step (S24) which is performed before theposition detecting step (S21).

In the film cutting step (S24), as illustrated in FIGS. 22 and 23 , theanisotropic conductive film 2 is first cut into the plurality ofanisotropic conductive film pieces 2Z. The anisotropic conductive filmpiece 2Z is a film piece in which the release film 4 is provided withone or the plurality of adhesive film pieces 5. Then, in the positiondetecting step (S21) after the film cutting step (S24), the position ofthe adhesive film piece 5 in the anisotropic conductive film piece 2Z isdetected by the imaging device 21. The anisotropic conductive film piece2Z may be provided with only one adhesive film piece 5 or two or moreadhesive film pieces 5. In the embodiment, the anisotropic conductivefilm piece 2Z is provided with only one adhesive film piece 5.

In the connection structure manufacturing method, since the anisotropicconductive film 2 is cut into the plurality of anisotropic conductivefilm pieces 2Z, it is possible to flexibly handle a case in which theadhesive film piece 5 is attached to a plurality of positions or theattachment direction of the adhesive film piece 5 needs to be changed.Then, since the position of the adhesive film piece 5 of the anisotropicconductive film piece 2Z is detected by the imaging device 21, it ispossible to improve the position accuracy of the adhesive film piece 5with respect to the adhesive surface even when the anisotropicconductive film 2 is cut into the plurality of anisotropic conductivefilm pieces 2Z.

Third Modified Example

In the above-described embodiment, a case in which the conductive filmaccording to the invention is applied to the anisotropic conductive filmhaving anisotropic conductivity has been described, but the conductivefilm according to the invention is not limited to the anisotropicconductive film having anisotropic conductivity. That is, the adhesivefilm piece and the adhesive film layer may not be formed such thatconductive particles are dispersed in the adhesive as long asconductivity is provided. As the adhesive film piece and the adhesivefilm layer in this case, metal oxides such as indium tin oxide (ITO),indium oxide, and tin oxide, those containing conductive fibers, and thelike may be included. Examples of this conductive fiber include metalfibers such as gold, silver, and platinum and carbon fibers such ascarbon nanotubes.

REFERENCE SIGNS LIST

1: wound body, 2 (2A, 2B1, 2B2, 2B3, 2C1, 2C2, 2C3, 2D, 2E, 2F1, 2F2,2F3, 2G1, 2G2, 2G3, 2H): anisotropic conductive film (conductive film),2Z: anisotropic conductive film piece (conductive film piece), 3: core,3 a: core material, 3 b: side plate, 4: release film, 5: adhesive filmpiece, 5A: adhesive film layer, 5A1: inner portion, 5A2: margin portion,5B: outline, 6: adhesive, 7: conductive particles, 8: second releasefilm piece, 8A: second release film, 8A1: inner portion, 8A2: marginportion, 10: connection structure, 11: first circuit member, 11 a: firstadhesive surface, 12: second circuit member, 12 a: second adhesivesurface, 21: imaging device, X: longitudinal direction, Y: widthdirection, Z: thickness direction.

1. A conductive film comprising: an elongated release film; and aplurality of conductive adhesive film pieces which are provided on therelease film, wherein the plurality of adhesive film pieces are arrangedin a longitudinal direction of the release film, and wherein an end edgeof the release film in a width direction of the release film and theadhesive film piece closest to the end edge are spaced apart from eachother.
 2. The conductive film according to claim 1, wherein each of theplurality of adhesive film pieces is provided with at least one hole. 3.The conductive film according to claim 1, wherein the plurality ofadhesive film pieces are spaced in the longitudinal direction of therelease film.
 4. The conductive film according to claim 1, wherein theplurality of adhesive film pieces have the same shape.
 5. The conductivefilm according to claim 1, wherein the plurality of adhesive film piecesare disposed at a center portion of the release film in a widthdirection.
 6. The conductive film according to claim 1, wherein theplurality of adhesive film pieces are disposed at an end portion of therelease film in a width direction.
 7. The conductive film according toany claim 1, wherein the plurality of adhesive film pieces are alsoarranged in the width direction of the release film.
 8. The conductivefilm according to any claim 1, wherein a gap of the plurality ofadhesive film pieces in the longitudinal direction of the release filmis 0.1 mm or more and 10 mm or less.
 9. The conductive film according toclaim 1, wherein a gap between an end edge of the release film and theadhesive film piece closest to the end edge in the width direction ofthe release film is 0.1 mm or more and 10 mm or less.
 10. The conductivefilm according to claim 1, wherein the release film has lighttransmittance.
 11. The conductive film according to claim 10, whereintransmittance of the release film is 15% or more and 100% or less. 12.The conductive film according to claim 10, wherein a haze value of therelease film is 3% or more and 100% or less.
 13. The conductive filmaccording to claim 1, further comprising: a second release film piecewhich is provided on the adhesive film piece.
 14. The conductive filmaccording to claim 1, wherein the adhesive film piece is formed suchthat conductive particles are dispersed in an adhesive.
 15. A wound bodycomprising: the conductive film according to claim 1; and a core onwhich the conductive film is wound.
 16. A connection structurecomprising: a first circuit member that includes a first adhesivesurface; a second circuit member that includes a second adhesivesurface; and the adhesive film piece according to claim 1 which connectsthe first adhesive surface and the second adhesive surface.
 17. Aconnection structure manufacturing method comprising: a filmmanufacturing step of manufacturing a conductive film in which aplurality of conductive adhesive film pieces are provided on anelongated release film and the plurality of adhesive film pieces arearranged in a longitudinal direction of the release film, and an endedge of the release film in a width direction of the release film andthe adhesive film piece closest to the end edge are spaced apart fromeach other; and a connection step of connecting a first adhesive surfaceof a first circuit member and a second adhesive surface of a secondcircuit member with the adhesive film piece of the conductive filminterposed therebetween.
 18. The connection structure manufacturingmethod according to claim 17, wherein the adhesive film piece is formedsuch that conductive particles are dispersed in an adhesive.
 19. Theconnection structure manufacturing method according to claim 17, whereinthe film manufacturing step includes an adhesive film layer forming stepof forming a conductive adhesive film layer on an entire surface of therelease film, an adhesive film layer cutting step of cutting theadhesive film layer along an outline forming an outer shape of theadhesive film piece, and a margin releasing step of releasing a marginportion corresponding to a portion other than the adhesive film piece inthe adhesive film layer from the release film along the cut outline. 20.The connection structure manufacturing method according to claim 19,wherein the adhesive film layer is formed such that conductive particlesare dispersed in an adhesive.
 21. The connection structure manufacturingmethod according to claim 17, wherein the connection step includes aposition detecting step of detecting a position of the adhesive filmpiece in the conductive film by an imaging device, an attachment step ofattaching the adhesive film piece to the first adhesive surface on thebasis of the position detected by the position detecting step, and anoverlapping step of overlapping the first adhesive surface and thesecond adhesive surface with the adhesive film piece interposedtherebetween.
 22. The connection structure manufacturing methodaccording to claim 17, wherein in the film manufacturing step, theconductive film is manufactured such that a second release film piece isprovided on the adhesive film piece.
 23. The connection structuremanufacturing method according to claim 22, wherein the filmmanufacturing step includes an adhesive film layer forming step offorming a conductive adhesive film layer on an entire surface of therelease film and covering an entire surface of the adhesive film layerwith a second release film, an adhesive film layer cutting step ofcutting the adhesive film layer and the second release film along anoutline forming an outer shape of the adhesive film piece, and a marginreleasing step of releasing a margin portion corresponding to a portionother than the adhesive film piece in the adhesive film layer and thesecond release film from the release film along the cut outline.
 24. Theconnection structure manufacturing method according to claim 23, whereinthe adhesive film layer is formed such that conductive particles aredispersed in an adhesive.
 25. The connection structure manufacturingmethod according to claim 22, wherein the connection step includes aposition detecting step of detecting a position of the adhesive filmpiece in the conductive film by an imaging device, an attachment step ofattaching the adhesive film piece to the first adhesive surface on thebasis of the position detected by the position detecting step, anoverlapping step of overlapping the first adhesive surface and thesecond adhesive surface with the adhesive film piece interposedtherebetween, and a second release film piece releasing step ofreleasing the second release film piece from the adhesive film piecebefore the attachment step.
 26. The connection structure manufacturingmethod according to claim 21, wherein in the attachment step, theadhesive film piece is attached to the first adhesive surface and thenthe release film is released from the adhesive film piece.
 27. Theconnection structure manufacturing method according to claim 21, whereinthe connection step further includes a film cutting step of cutting theconductive film into a plurality of conductive film pieces in which oneor the plurality of adhesive film pieces are provided in the releasefilm before the position detecting step, and wherein in the positiondetecting step, the position of the adhesive film piece of theconductive film piece is detected by the imaging device.
 28. Theconnection structure manufacturing method according to claim 17, furthercomprising providing at least one hole in each of the plurality ofadhesive film pieces.